Human brain has two components one the rational brain and the other limbic brain.
Whereas rational brain helps to plan for the future , the limbic or emotional brain often referred as the “elephant” is responsible for emotions.
Thus the rational or analytical part of the brain is often referred to the “Planner” whereas the emotional brain is known as the “Doer”.If emotional brain is the elephant the rational brain is the “rider”.
Thus human behavior is an interplay of these two components.
Chip and Dan Heath mention this in the book titled “Switch”.